1. Field of the Invention
The present invention generally relates to keyboard apparatus and, in a preferred embodiment thereof, more particularly relates to a notebook computer keyboard having a deflectable base plate reinforced with stiffening ribs secured thereto and interdigitated with rows of keys mounted thereon.
2. Description of Related Art
As computer keyboards, particularly notebook computer keyboards, become thinner and thinner the keyboard stiffness (i.e., resistance to downward deflection while being typed on) is correspondingly being reduced. If the keyboard lacks stiffness and the system does not provide sufficient support to the keyboard, the keyboard can feel xe2x80x9cspongyxe2x80x9d while the customer types on it. This keyboard deflection can be undesirably equated by the user to poor quality construction.
As typically constructed, notebook computer keyboards include a deflectable metal base plate on the top side of which the depressible key portions of the keyboard are mounted. Conventional methods for increasing the stiffness of keyboards of this type include (1) increasing the thickness of the keyboard base plate, (2) changing to a stiffer base plate material (for example, from aluminum to cold rolled steel), and (3) attaching stiffener plates to the bottom side of the base plate.
Each of these three conventional approaches to stiffening the deflectable base plate portion of a notebook computer keyboard carries with it at least one disadvantage. For example, there is typically a weight penalty when the keyboard base plate material is changed to a stiffer material.
If the keyboard base plate thickness is increased, or stiffener plates are secured to the bottom side of the base plate, there are thickness and/or weight penalties.
From the foregoing it can readily be seen that a need exists for improved structure for providing a keyboard of the type generally described above with increased stiffness.
It is to this need that the present invention is directed.
In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, an electronic device, representatively a portable notebook computer, is provided with a specially designed structurally reinforced keyboard.
The keyboard, in a preferred embodiment thereof, includes a deflectable base member having a top side, a parallel plurality of laterally spaced rows of depressible key structures supported on the top side of the base member, and a plurality of elongated stiffening ribs longitudinally extending parallel to the key rows, anchored to the top side of the base member, and interdigitated with the key rows. Because of the unique placement of the stiffening ribs on the top side of the base member, coupled with the interdigitation of the ribs with the key rows, the ribs substantially stiffen the base plate, and thus the entire keyboard, from the inside of the keyboard. In this manner a desirable enhancement of the overall rigidity of the keyboard is achieved without undesirably increasing its overall height.
Preferably, the deflectable base member has a generally plate-shaped configuration, and the stiffening ribs have generally plate-shaped main body portions anchored in a beam-like orientation on the top side of the base member. In a preferred configuration thereof, each stiffening rib has a lower side edge from which an elongated securement tab portion laterally projects transversely to the main body portion of the stiffening rib, and the securement tab portion of each stiffening rib is anchored to the top side of the deflectable base member.
According to another aspect of the invention, each of the key structures includes a key member having a bottom side and being movable toward and away from the top side of the base member between downwardly depressed and upwardly extended positions, respectively, and the bottom sides of the key members have notches formed therein and positioned to receive portions of the securement tabs when the key members are moved to their downwardly depressed positions.
In accordance with another feature of the invention, the main body portions of the stiffening ribs have top side edges, each of the key members has an upper side, and the top side edges of the stiffening rib main body portions are positioned so as to be located generally level with the upper side of each key member when the key member is moved to its downwardly depressed position. In this manner, the stiffening ribs do not interfere with the depression of the key members or undesirably come into contact with the keyboard user""s fingers as the key members are depressed during typing on the keyboard.